Instead of the worm drive systems discussed here, a bevel equipment system could possibly be used to convert rotation to linear motion. This might offer greater efficiency to a machine screw jack due to it making a rolling contact as opposed to the sliding get in touch with of worm drive elements. It could, however, come at a greater initial cost and does not cover as higher ratio range as worm drives.
Also called power screws, lead screws come with several different types of thread profile which are ideal for different applications. Acme lead screws are defined by their trapezoidal thread profile and 29° flank angle and are commonly found in American Imperial machine screw jacks. An alternative solution to the Acme lead screw in a machine screw jack would be a square lead screw.
European or other worldwide screw jacks utilise a trapezoidal lead screw with a 30° flank angle and complies to an ISO metric regular.
Ball screw jacks require the thread of the business lead screw to get a profile that allows for the travel of the balls. To improve load distribution and minimise put on, the ball screw monitor includes a gothic arch profile.
Popularity of the trapezoidal screw thread originates from the fact that it is simpler to machine and is therefore less expensive than square and ball screw thread forms. Additionally, because of the large region of contact between the business lead screw threads and the worm wheel, there is certainly a large load carrying capacity. This outcomes in high friction which is harmful to efficiency but does mean the system is more likely to be self-locking. This low effectiveness implies that such screw jacks are more suited to non-continuous or intermittent operation.

Many applications do not warrant the excess expenditure of a ball screw jack given that they do not require continual drive. In configuring a screw jack a prediction is constructed of the frequency of actuation which will point to the correct screw jack to end up being selected.

Translating Design Jacks are most often selected. With this design, a driven input worm works on an interior worm gear causing the lifting screw to increase or retract. Operation needs that rotation of the lifting screw end up being prevented. This rotation it restrained whenever two or more jacks are tied to the same load.
Keyed Design Jacks are utilized any moment rotation of the lifting screw isn’t restrained. For instance, when you must lift the jack to meet a load. This is one way they work: A key, fixed to the jack housing and inserted into a keyway milled into the length of the lifting screw forces the lifting screw to translate without rotating.
Keyed For Travelign Nut Style Jacks (KFTN) are another choice. These jacks have a fixed size lifting screw that rotates. Loads are mounted on a flanged “touring” nut that translates along the length of the rotating screw. This kind of jack is ideal for applications that cannot support a screw protection tube or that require a flush mount
The worm wheel acts on the ball screw (via the ball nut) which actuates the lead screw. This technique offers greater efficiency between the insight and the useful output weighed against a machine screw jack. Furthermore, it allows for higher actuation speeds and, because of the low friction, is very durable. However a ball screw jack isn’t inherently self-locking and, because of its improved precision components, the initial outlay is greater. The resulting improved effectiveness however implies this could be offset against smaller drive train parts and a significant decrease in the necessary power.